COVID-19 infection associated with lower live birth rates in fresh embryo transfer cycles.

Background and aimsIt is important to clarify the impact of COVID-19 on ART outcomes and to develop evidence-based guidelines for deciding whether to proceed with or cancel in vitro fertility procedures in infected patients. This study aims to clarify the specific impacts of COVID-19 infection on the live birth rates (LBR) and fetal outcomes in patients undergoing fresh embryo transfer (fET) cycles.MethodsThis retrospective study analyzed 1,025 fresh embryo transfer cycles from January 2021 to January 2023. We compared pregnancy and neonatal outcomes between the non-infected group (n=762) and the COVID-19-infected group (n=263). Additionally, we stratified the infected group into subgroups by two criteria: time of infection, with or without fever and partner infection status, and further compared pregnancy outcomes of these subgroups. Univariate and multivariate logistic regression analyses were performed to assess differences in pregnancy and neonatal outcomes between non-infected and COVID-19-infected individuals.ResultsThe newborn’s gender, birth height and birth weight were comparable between the infected and uninfected groups. However, the COVID-19 infection group exhibited a lower LBR with an adjusted odds ratio (OR) of 0.655 (95% confidence interval (CI: 0.483 to 0.887; P = 0.006) and a higher mid-to-late miscarriage rates with an adjusted OR of 7.929 (95% CI: 2.651 to 23.714; P < 0.001) compared with the non-infections group. Stratified analysis showed that infections occurring between 28 and 84 days prior to oocyte retrieval accompanied by fever of ≥ 38.5°C resulted in a lower LBR (OR: 0.467, 95% CI: 0.290 to 0.752; P = 0.002 < 0.025) after Bonferroni’s correction. Additionally, the dual-partner infection group demonstrated a significantly reduced LBR (OR: 0.591, 95% CI: 0.421-0.830; P = 0.002 < 0.025) compared to uninfected controls.ConclusionCOVID-19 infection was associated with a lower LBR in fET cycles, especially when: infection occurred 28–84 days before oocyte retrieval with fever ≥ 38.5°C, or dual-partner were infected. Subsequent multicenter studies enrolling a significantly larger cohort of infected women or couples are essential to validate this finding.